Google Play, Amazon and Pricing

So I recently got a nastygram from Amazon pricing, decrying the fact that one of my books, "Banish the Darkness" is on sale in Google Play Canada for $2.99CA, yet it is listed for $4.04 on Amazon's Canadian site, and informing me to change my pricing on Amazon to match.

The problem is, I didn't set the price that low, and when I went to Google Play, there are a bunch of my books discounted, and I have no idea why. I cannot get to the CA store to verify what Amazon claims, but I am even more concerned that an already discounted compendium I JUST released has been further discounted at Google Play. Would like some guidance on how pricing is set at Play, and also at other outlets. Why are some of these books discounted when the pricing on Lulu hasn't been?

Except I can't check the Google Play Canada store - the normal price of my book is 2.99 US so I worry this is currency mismatch that is causing Amazon to freak out and threaten to pull my book. It's part of a series, so anyone who purchases the series will be frustrated.

I suspected what you said below, and it would explain why Kobo, etc take over 50% of my book price - it's so they can still make a lot of profit but skim off just enough to make them 'more attractive'. I understand being competitive, but it is unpleasant being in the middle of Google and Amazon in a p-ssing contest over pricing and I can't even go and check myself! I've tried play.google.ca, I've tried looking for a setting at the Play store to verify this and I can't.

So I recently got a nastygram from Amazon pricing, decrying the fact that one of my books, "Banish the Darkness" is on sale in Google Play Canada for $2.99CA, yet it is listed for $4.04 on Amazon's Canadian site, and informing me to change my pricing on Amazon to match.

The problem is, I didn't set the price that low, and when I went to Google Play, there are a bunch of my books discounted, and I have no idea why. I cannot get to the CA store to verify what Amazon claims, but I am even more concerned that an already discounted compendium I JUST released has been further discounted at Google Play. Would like some guidance on how pricing is set at Play, and also at other outlets. Why are some of these books discounted when the pricing on Lulu hasn't been?